Thread-controlling mechanism for sewing-machines.



G. p. GORGORAN. A THREAD GONTROLLING MEGHANISM FOR SEWNG MACHINES.

APPLIATION FILED APR.7, 1911. 1,1 34,034. Patented Mar. 30, 1915.

UNITED sTATEs PATENT oEEicE.

GEORGE L. CORCORAN, OF ST. LOUIS, MISSOURI, ASSIGNOR. TO CHAMPION SHOE MACHINERY'COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

THREAD-CONTROLLING- MECHANISM FOB SEWING-MACHINES'.

Patented Mar. 30, 1915.

Original application filed December 5, 1910, Serial No. 595,799. Divided and this application led April 7,

T0 all 'whom it may concern Be it known that I, GEORGE L. ConooRAN, a citizen of the United States,- andresiding at St. Louis, in the State yof Missouri, have invented certain new and useful Improvements in Thread-Controlling Mechanism for Sewing-Machines, of which the following is'` of the measured thread in accordance with the thickness of the work. In accordance with this invention the thread is locked while it is taken up and while the stitch is set, and thereafter it is released and the thread for the next stitch is measured from the supply.

One `of the 'objects of this invention is to construct a thread-lock which is adapted to lock and release the thread and provide means whereby the action of the thread-lock can be controlledand varied, preferably in accordance with the thickness of the work, in order to regulate the'setting of the stitches and the measuring of the thread for the stitches.

Another object is to improve the threadlock as to details so that it will be simple in construction and easy to assemble and disassemble.

Further objects will appear from the detail description taken in connection with the accompanying drawings in which,

Figure 1 is a side elevation of the head and a part lof the work support of a sewing -machine showing this invention applied thereto, Figs. 2 and 3 are longitudinal sections of the thread-lock taken at right angles, and Fig. 4 is a detail plan view of the thread lock.

Similar reference characters are used as in the application referred to, and reference is had to said application for details of construction there shown.

Referring to the drawings, 10v designates lthe work support, and 11 the headof a-sewing machine, which in this particular inlto a suitable vtreadle (not shown).

stance is of the lock-stitch type. An awl 12 is supported by the awl-bar 13 which reciprocates vertically in the head of the machine and is guided at its upper end by a cross head 14 engaging a guide 15. A hooked needle 16 enters the hole made in the stock S from below. Looper mechanism of well known construction and comprising fingers 17 and 18, is arranged to loop the needle which is arranged to be moved vertically in bearings in the head. The upper end of the presser foot bar has secured to it a laterally extending lug or finger, and a toe 23, of a lever 24 pivoted at 25 in the head, extends underneath the lug, and the opposite end of the lever is connected by a treadle rodl1 1216 e presser foot is normally pressed down on the work by means of a leaf spring 27, and this presser foot can be raised by means of the treadle through the connections shown.

'Ihe needle thread T from the main supply 30 passes through a thread lock A, over a guide 31, and through the wax pot 32. An arm 33 is pivoted on the wax pot or to any other suitable part of the machine head, and is under the tension of a spring 34, which normally tends to move the free end of the arm to the right, Fig. 1. Arms 35 and 36 are pivoted to the head of the machine and are provided at their free ends with guides for the thread. The arm 36 is secured to an actuator shaft 37 which has also rigidly secured to it an arm 38 connected by a link 39 to the arm 35. By means of this construction the arms 35 and 36 move toward 43 to 4a suitable actuating cam on the main' shaft.

The thread-lock comprises a cylindrical body 50 which is bored and provided with a securing flange 51, so that the lock can ioo sleeve 52 and a knurled locknut 53. A- knurled head 54 is mounted onl a shank 55,

the end of which is threaded to receivea collar 56 which affords an abutment for one the thread. The thread is alsoy tion of the stitch.v

end of a spring 56, the other end of which bears against a shoulder formed inthe lock body. The shankis provided with a hardened end-:57, .and its-.'upperfend with a slot 58 for the thread. The collar 56 is locked against turning by means of a screw 59 engaging a slot 59 in the lock body, and the head 54 is provided for a similar purpose with a guide pin 60 engaging a socket in the lock bod This guide pm is screwed into 4the hea 54 and locked in position b'ymeans of a lock nut 6l. The co erating faces of the plunger head 54 and s eeve 52 are coned as shown in the drawing for the purpose of gripping the thread. A tappet 62 slides in the bore of the lock body and is prevented from vdropping out by means of a screw 63 engaging a slot 64'.l The upper end of this tappet is inclined to correspond with lthe incline on a sliding wedge 64 which is guided b the slots 64. The wedge 64 is connecte by a link'65 to one arm o a lever 66 pivoted atV 25. The other arm of the lever is lconnected by a link 67 to an arm 68 'secured to and projecting rearwardly from the upper end of the presser foot bar. The tappet 62 is'arranged to be engaged by the end 69 of e lever 42.A s A tension device is-arranged between the lock and the thread suppl so as to deliver the thread to the klock unl er tension. This tension device comprises a bracket 70 secured to the lock body and provided with evesy 71 and 72 for receiving and guiding gripped between a pair of tension plates'or dis s 73 ressed` together by means of a spring 7 on a threaded shank secured the tension of this spring can be regulated by means of awing nut 75.

The arms 35 an 36 constitute together a take-up mechanism the function of which is to take' u" the s thread,set the stitch, and give up the t read to the needle and the shuttle in the forma- In 'this case, however, the take-up mechanism erforms an addi tional function, namely t at of'drawin or measuring the thread for the next st1tch. This is 'accomplished by constructing the take-up mechanism so that it has two actions or movements,one of which is the take-up and stitch setting action, and the other of which is a thread drawing or measuring action. In the preferred form the lock is maintained closed until the stitchv isset'and then it is opened to permit the 4they are l relation.

to the bracket, and

or takevup membersl" vthe take-up mechanism, lso t take-up .mechanism in the -last part of its movement to draw or measure the thread for the. next. stitch. They lock is' closed to grip thethread between the plunger head 54 and the collar 52`byv means of the spring 56, and the threadV is released by the engagement of the end 69 of the lever42 with the tap et 62. The raising of the tappet causes tlie wedge 64 to be ymoved upwardly to engage the `end`5'7 of the plunger `so as to raise it against the tension of its spring 56A Both the lock .and .the .take-up mechan-ism are operated from the lever 42 so that f interconnected tol operate in timed Assume that Vthe stitch has been formed and that the arms 35 and 36 have moved toward each other so as to give up the thread during the formation of the stitch. As the arms 35and 36 'again move away from each other, the thread will be taken upv and the stitch will be vset against the tension of the siprin'g 34, the thread being at this time rmly gripped by the thread-lock A. During vthe latter part of this lmovement of the arms 35 and 36 the lever 42 will engage the tappet 62 to open the lock A and permit thread for the next stitch to be drawn by the take-u mechanism. Thereafter the lock will be and the thread will be again given up -by the take-up mechanism durlng the formation of the next stitch'.

It will be evident ply of thread must with the thickness of the stock. lThis is accomplished by Vproviding an adjustable that the measured supamount `o such llost motion can be varied yaswill beobvious by referring to Figs. 2 and 3. Thus ifthe wed eis moved to the left, Fig. 2, the amount o lost'moti'on will b e decreased, and if moved to the right, will be increased. A decrease in the lost motion will cause the -lock tobe opened earlier in the take-up and lock settin ,movement of of thread drawn or measured isinereased, keepin in mind that the take-up mechanism hasa yxed stroke. 4 An increase in the lost motion will have the reverse effect. Due.. to the interconnectionclosed be varied in accordance v work engaging member which varies inits' the position of the wedge, Kthe 12o atthe amount of the presser foot andthe wed e 64 an upward movement of the presser oot will cause the lwed ge to move to the left Fi 1 and 2,.-and a downward movement lwil cause the' wedge to move to,

lso'I and measured for every thickness.

35 under tension so 40 It will therefore 5 stitch will be increased. The levers and wedge are so designed that the amount of thread drawn and measured is in accordance with the thickness of the work, so that the correct amount will be automatically drawn This insures that the stitch lock will be set at a uniform distance in the work irrespective of its thickness.

It is sometimes necessary to vary the timing of the opening of the lock independently of the automatic mechanism, for instance, 1n order to adjust the machine for stitches of different lengths or for preliminary adjustments for the tension of the thread. This can be accomplished by varying the time of the opening of the lock by independently varying the amount of lost motion referred to above. By referring to Fig. 2 it will be seen that if the sleeve 52 is raised the amount 0f lost motion will be increased, and if lowered decreased. The mechanism can therefore be manually and independently adjusted by adjusting the knurled sleeve 52,

this sleeve being locked in adjusted position by means of the lock nut 53.

In order to insure accurate measurmg of the thread, a tension device is placed between the lock and the thread supply. In

this way the thread is deliveredvto the lock that overthrow of thread is prevented. The spring 74 is, however, a comparatively light spring, so that the tension on the thread will only be suilicient to prevent overthrow.

be seen that in accordance with this invention the thread is locked during the take-up and stitch setting movement of the take-up members, and is released by opening the lock during the latter part of the take-up stroke of the take-up members. The take-u members have a fixed stroke wlth a fixe point at the end of the stroke, and by timing the point of opening of the thread-lock, the duration of the releasing action of the lock, and therefore the duration of the thread drawing action or movement of the take-up members, can

be varied. By utilizing the"takeup members for drawing the thread, the number of parts are reduced to a minimum resulting in simplicity of construction. The lock is so constructed that it can be easily assembled are lockedv so. as not to become loose.

While only one embodiment of this invention has been shown and described, it will be obvious that the invention may be embodied in different forms. It is also obvious that various changes lmay be made in details of construction without departing from this invention, and it is therefore to be understood that this invention is not to be limited to the specific construction shown and. described.

Having thus described the invention what is claimed is:

1. In a sewing machine, comprising a tubular body,

a thread-lock a plunger having a plunger head, an adjustable sleeve on said body, said sleeve and head having cooperating thread gripping faces, and a spring for moving said gripping faces together.

2. In a sewing machine, a thread-lock comprising a tubular body, a plunger having a plunger head, said body and head having coperating thread gripping faces, a spring for moving said gripping faces' together, and a tension device mounted on said body.

3. In a sewing machine, a thread-lock comprising a support and a movable member having coperating gripping faces, an actuator, and an adjustable wedge carried by said support and interposed between said actuator and movable member.

4. In a sewing machine, a thread-lock comprising a tubular body and a plunger having coperating gripping faces, a stem on said plunger, a tappet carried by said body, and an adjustable wedge between said stem and tappet.

In testimony whereof I affix my signature in presence of two witnesses.

. .GEORGE L. conocieran.

Witnesses:

J. H. BRUNINGA, GERTRUDE HnssING.

vnand"f'disassembled, and all its moving parts 

